Multifunctional MMICs – Key Enabler for Future AESA Panel Arrays

Central building blocks for modern phased arrays with Active Electronically Steered Antennas (AESA) are single channel Transmit/Receive (T/R) modules, used in different platforms today, e.g., in antennas for ground surveillance and security radar or in airborne fighter nose radars. Up to hundreds of T/R Modules (TRM) are mounted on so called “plank structures” and with an arrangement of planks the aperture geometry of the AESA is realised perpendicular to the plank direction. Up to now, the receive-, transmit- and control functions of the TRMs typically are realized with single-function GaAs- and Si- MMICs (Monolithic Microwave Integrated Circuit). In order to provide a considerable grating lobe free field of view these brick-style TRMs must fit the half-wavelength grid demand. Therefore the final module width for X-Band usually is limited to 15mm (max). New AESA equipment for UAVs (Unmanned Aerial Vehicles) will have to be integrated in even smaller volumes and often have to match with extremely small hardware-volume and geometry factors, especially with regard to installation depth. Within the last years the development of semiconductor technologies like GaN (Gallium Nitride) and SiGe (Silicon Germanium) have shown a high potential for compact RF solutions by combining several functionalities in one MMIC. HENSOLDT has developed GaN based frontend MMICs including LNA (Low Noise Amplifier), HPA (High Power Amplifier) and SWITCH (replacing the circulator) functionality and SiGe based CoreChips providing both phase- and amplitude setting of the RF signal and control/command and memory functions. With these two multifunctional MMICs and appropriate packaging technologies, the development of a new generation of AESA panel arrays based on tile architecture is rendered possible. Herein the single T/R channels form part of a 3D T/R active zone embedded in an RF multilayer board with the radiating element on its top layer. This modern tile array approach will allow flat antenna solutions with a drastically reduced installation depth.